English▸ noun Linguistics a writing system in which a character typically represents a consonant and vowels are an optional secondary feature, used for Semitic languages such as Arabic and Hebrew:
the four abjads still in use today developed from a common ancestor.
– ORIGIN Arabic abjad, denoting the Arabic alphabet, from the initial letters of alif, bā', jīm, and dāl, the first four letters of the Arabic alphabet in its historical order.